diff --git a/drivers/io/io_storage.c b/drivers/io/io_storage.c
index fe6542368e4fa6799d898e6a5e07f4343315026a..0918de0a23daefb7ddb14c902e84818d266b1dc4 100644
--- a/drivers/io/io_storage.c
+++ b/drivers/io/io_storage.c
@@ -94,7 +94,7 @@ static void set_handle(uintptr_t *handle, io_entity_t *entity)
 static int find_first_entity(const io_entity_t *entity, unsigned int *index_out)
 {
 	int result = -ENOENT;
-	for (int index = 0; index < MAX_IO_HANDLES; ++index) {
+	for (unsigned int index = 0; index < MAX_IO_HANDLES; ++index) {
 		if (entity_map[index] == entity) {
 			result = 0;
 			*index_out = index;